Selective conversion of decane into branched isomers

Differences between MFI- and MEL-Type Zeolites in Paraffin Hydrocracking

“…An examination of the published n-C 10 hydroconversion data (Table 1 ( 5, 19-22)) shows that only one paper (19) discusses an MFI-type zeolite catalyst that yields a secondary hydrocracking product slate with a C 5 fraction consisting of close to 50% i-C 5 . At 46% n-C 10 hydroconversion, this catalyst loses only 7% of the C 10 feed through hydrocracking (%C 10 hydrocracked, Table 1), whereas at that same conversion level the other catalysts lose more than 35% of the C 10 feed (5,(20)(21)(22). This low primary hydrocracking selectivity, the small amount of secondary hydrocracking (mol C 7 hydrocracked/100 mol C 10 hydrocracked) at a high % n-C 10 hydroconversion, and the high percentage of branched paraffins in the secondary hydrocracking product slate (1/5 7 x=4 % i-C x ) ( Table 1, also explains formula) all indicate that this particular MFI-type zeolite catalyst exhibits minimal mass transport and hydrogenation rate limitations (10,(41)(42)(43).…”

“…Table 1) that is characteristic for mass transport or hydrogenation rate limitations. The preponderance of studies on Pt-loaded MFI-type zeolite catalysts in which the n-C 10 hydroconversion rate was not dominated by the acid catalyzed reactions could explain why the premature i-C 10 hydrocracking used to be considered so important (5,10,19,22).…”

“…As the thermodynamic adsorption data relate to the shape selective properties that are intrinsic to a zeolite structure, we develop a criterion to identify catalytic data that are unimpaired by mass transport or hydrogenation rate limitations. A subsequent scrutiny of the published n-C 7 (8,18) and n-C 10 (5,(19)(20)(21)(22)(23) hydroconversion data using this criterion shows intrinsic differences in paraffin hydroconversion between MFI-and MEL-type zeolites. Simulated C 10 adsorption data are then used to explain the observed differences in the hydroconversion of n-C 10 and of complex feedstocks and the absence of such differences in a publication (8) on the hydroconversion of n-C 7 .…”

Molecular Simulations of Zeolites: Adsorption, Diffusion, and Shape Selectivity

“…As a consequence, if we use the reaction scheme in Figure 51, the product distribution obtained from TON-type zeolites comprises many monobranched (and some dibranched) isomers and their hydrocracking products, whereas the distribution obtained from FAU-type zeolites comprises many dibranched (and some tribranched) isomers and the hydrocracking products. 459 Clearly, differently sized and shaped zeolite pores will interact differently with differently sized reactants, reaction intermediates, and products. As a result, the zeolite topology can leave its"fingerprint" on a particular product distribution.…”

“…424 Whereas progress has been made in establishing and understanding external surface reactions 433,[454][455][456] (variously called "nest effects" 457 or "pore mouth 424,456,[458][459][460] " and "key-lock [461][462][463][464] " catalysis), the (other)"special effects" have mushroomed into a myriad of phenomena, each with their individual name. Apparently, it became fashionable to simply classify the individual catalytic phenomena instead of trying to arrive at a systematic understanding at a molecular level.…”